I am Sharing My Experience while migrating Navision version 5 to NAV13 we have find gaps how to improve the performance of existing qvw. I Feel that if existing application is satisfying your needs of business then try to change those area where you need some improvements instead of starting with ZERO.

so far I am happy with Qlik View report which I created 5 year ago. And I don't see any gap when I chang the accounting software to Microsoft accounting package.

By the way did you generate all raw data file with your new account system and use back all QVW script ?

My issue is the pass effort I have put in is a lot . And I don't think I can duplicate it again from ZERO. that I'd the main reasons I think it is better to fix the raw data format For my new account system so I can use back all QV report.